ETE Riachão Grande Wastewater Treatment Plant, São Bernardo do Campo, São Paulo

ETE Riachão Grande is a wastewater treatment plant located in São Bernardo do Campo, within the São Paulo metropolitan area, Brazil. The facility serves a population of approximately 7,721 residents, classifying it as a small-scale treatment plant in one of Brazil's most densely populated regions. As a plant in Brazil, it operates under the National Environment Council (CONAMA) resolutions and state-level environmental regulations, which mandate appropriate treatment for wastewater before discharge. For small agglomerations like this, secondary treatment is typically required to protect water quality in receiving bodies. The plant's treated effluent likely discharges into local watercourses that drain into the Billings Reservoir or the Tietê River basin, ultimately flowing into the Paraná River system. This watershed supports diverse aquatic life and provides water for millions of people in the São Paulo region, making effective treatment crucial for public health and ecosystem integrity.

The plant is situated in the Alto Tietê watershed, which drains into the Billings Reservoir, a critical water supply source for São Paulo. Downstream, waters flow into the Tietê River, a major tributary of the Paraná River basin. The region's aquatic ecosystems support diverse fish species and provide important ecological services, including water purification and flood control.